The conventional throttle positioning system on an automotive engine is a mechanical linkage between the throttle and an operator control such as an accelerator pedal. In the conventional system, an input from the engine operator is directly converted to a particular throttle position, and abrupt movements of the accelerator pedal cause abrupt changes in throttle position and in the pressure in the engine induction manifold downstream of the throttle. In addition, changes in engine load cause the operator to move the accelerator pedal and throttle in search of a new throttle position which will provide the desired engine operation.
It is well known that abrupt and unnecessary changes in throttle position and manifold pressure inhibit operation with minimum emissions and fuel consumptions and, in addition, lead to annoying shift patterns with some automatic transmissions. The operator of the conventional throttle positioning system therefore has the burden of avoiding abrupt and unnecessary changes in throttle position to enjoy minimum emissions and fuel consumption and smooth vehicle operation.